Matteo Mazzarini

Matteo Mazzarini (Italy)

mazzarini @ uni-heidelberg.de

The impact of satellite galaxies on the Milky Way disc

The galaxy in which we are, the Milky Way (MW), is a disc galaxy surrounded by a number of dwarf satellites that orbit around it. The way these objects can impact on its dynamical evolution is still debated and under investigation. In addition to this, the dynamical properties and the final distribution of these impactors is not yet completely clear. Recent works via N-Body simulations have focused on the vertical heating of the MW disc due to the interaction with these substructures at redshift zero. Now, we aim at studying the properties of the satellite debris. In particular, we are interested in the final distribution of the Dark Matter (DM) and baryonic components of the satellites that accrete onto the disc. This will give us further possibility to investigate the metal enrichment and the time evolution of Star Formation (SF) in the MW disc at different galactocentric distances.After an initial test performed employing the tree-codes ChaNGa and GADGET-2, based on a comparison with results obtained with the Particle-Mesh code SUPERBOX-10 via pure N-body simulations and intended to choose our candidate code, we perform full high-resolution numerical simulations of 4 to 6 Gyr interaction between the satellite galaxies and the MW disc. The candidate code may include another release in the Gadget family, such as the upcoming GADGET-4. For our simulations, we need to switch on gas dynamics, activate SF effects and include Supernovae feedback. By doing this we will be able to turn to a more realistic description of the process of matter accretion and metal enrichment in the MW disc. Moreover, running high-resolution simulations will allow us to determine possible effects of dynamical friction exerted by the MW halo on the satellites. The resulting picture may be compared with recent data such as the ones obtained from GAIA observations. This is important in order to put possible constraints on the fate of the dwarf impactors after their interaction with our galaxy and on the past evolution of the MW disc.